Unitary bi-stable code wheel for mechanical conveyors and sorting apparatus

ABSTRACT

This disclosure relates to a code wheel for a conveyor system such as employed in a sorting apparatus for letters and other articles. The wheel is of unitary construction and has a rim that can be translated from one to the other of two stable positions. The connecting support for the rim may be either a plurality of pivotally mounted spokes or an approximately conical web where the length of the respective spokes or of the conical element is greater than the difference between the rim radius and the hub radius. During translation of the rim from one stable position to the other, distortion occurs either in the rim of the spoked embodiment or in the web. Material resistance to this distortion serves to urge the rim to its nearest stable position.

United States Patent lnventors Appl. No. Filed Patented Assignee UNITARY BI-STABLE CODE WHEEL FOR MECHANICAL CONVEYORS AND SORTING APPARATUS 10 Claims, 7 Drawing Figs.

[15. Cl 29/110 Int. Cl 86% 5/02 Field of Search 29/ l 29, 110,126, 127, 128; 74/23001, 230.05; 198/1, 38

References Cited UNITED STATES PATENTS 1,612,990 1/1927 Silverstein et a] 29/126X 3/1930 Pflimlin 29/128X Primary Examiner-Alfred R. Guest Attorney-Carl Fissell, Jr.

ABSTRACT: This disclosure relates to a code wheel for a conveyor system such as employed in a sorting apparatus for letters and other articles. The'wheel is of unitary construction and has a rim that can be translated from one to the other of two stable positions. The connecting support for the rim may be either a plurality of pivotally mounted spokes or an approximately conical web where the length of the respective spokes or of the conical element is greater than the difference between the rim radius and the hub radius. During translation of the rim from one stable position to the other, distortion occurs either in the rim of the spoked embodiment or in the web. Material resistance to this distortion serves to urge the rim to its nearest stable position.

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PETER T DI PAOLO JR. JOSEPH LCARBjN E BY A UNITARY BI-STABLE CODE WHEEL FOR MECHANICAL CONVEYORS AND SORTING APPARATUS BACKGROUND OF THE INVENTION This invention relates to a code wheel for a conveyor apparatus and more particularly to a bistable code wheel for employment with a sorting apparatus for sorting letters, packages and other articles.

Mechanical sorting apparatus for which the present invention is adapted are of the type that include a conveyor upon which a plurality of trays are mounted which trays are provided with a releasable bottom such that the contents of each tray can be dropped into a particular selected one of a plurality of receptacles mounted beneath the conveyor. With such a system, the conveyor can pass a number of stations and articles destined for certain preselected receptacles are placed in the appropriate tray. After the respective trays have passed along the conveyor past all of the contributing stations, the trays are passed over the plurality of receptacles and the contents of each tray are deposited in the corresponding preselected or addressed receptacle. The system can also be employed to distribute articles from a single station to a plurality of receptacles. Such systems can be employed to sort and distribute mail, checks and the like.

In order to determine the time at which each of the respective trays has been aligned over its corresponding bin or receptacle, each tray is provided with a plurality of code wheels mounted on a single axis and adapted to be placed in one of two positions, in essence, to form a binary code or address corresponding to the desired receptacle. Each receptacle, in turn, is provided with a plurality of grooved tracks over which the code wheels ride and each of the grooved tracks can be placed in one of two positions corresponding to the binary code or address associated with the receptacle. With this arrangement, the code wheels for a particular tray will ride above the grooved tracks until such time as the code wheel configuration corresponds to the grooved track configuration, whereupon the code wheel axis will be allowed to drop slightly and this motion can be utilized to release the bottom of the tray to deposit its contents in that receptacle.

Inherent in a machine of the type described above is the requirement that each code wheel be adapted to be placed into different stable positions. Prior art code wheels have been of the type that were adapted to slide along an axis having two v detent positions with the code wheel being provided with an appropriate spring biased ball detent to restrain movement of the code wheel from one position to the other. While such code wheels are satisfactory, the amount of force required to move the code wheel from one position to another is dependent upon the characteristics of the detent and its spring bias. Furthermore, such code wheels require a certain amount of machining and assembly of the code wheel, the detent ball and the spring onto the code wheel axis. Since a relatively large number of code wheels can be required for a given system, it is desirable to reduce the cost of the manufacture of the code wheels and their assembly.

It is, then, an object of the present invention to provide an improved code wheel for a sorting device and system.

It is still another object of the present invention to provide an improved code wheel capable of being moved from one to the other of two stable positions relative to its axis.

It is still another object of the present invention to provide an improved code wheel that may be readily assembled in quantity upon the code wheel axis.

It is still a further object of the present invention to provide an improved code wheel of economical manufacture.

SUMMARY OF THE INVENTION In order to achieve the above objects, the code wheel of the present invention is adapted to be molded into a unitary form with the rim of the wheel being provided with axial movement relative to the hub of the wheel. To this end, the rim is attached to the hub by way of pivotally mounted spokes or a flexible conical web where the respective lengths of the spokes or the conical element of the web are greater than the difference between the rim radius and the hub radius such that the rim will have two stable positions which are symmetrically offset from the hub joint with the spokes or web.

A feature, then, of the present invention resides in a unitary code wheel having a rim movable from one to the other of two stable positions relative to the wheel hub which rim is flexibly connected to the hub by way of a plurality of spokes or a conical web where the length of the spokes or a conical element is greater than the difference between the radius of the rim and the radius of the hub.

Other features reside in the provision of rim guides to prevent the skewing of the rim in transfer from one stable position to another, the necking down of the respective spokes or conical web where they make connections with both the rim and the hub, and in the particular materials of which the code wheel of the present invention is formed. The latter two named features are directed to the obtainment of the desired degree of flexibility for employment of the present invention.

DESCRIPTION OF DRAWINGS These and other objects, advantages and features of the present invention will become more readily apparent from a review of the following specification when taken together with the drawings wherein:

FIG. 1 is a plan view illustrating a sorting device with which the present invention is to be employed;

FIG. 2 is a sectional view of a portion of FIG. 1;

FIG. 3 is a plan view of one embodiment of the present invention;

FIG. 4 is a sectional representation of the embodiment of FIG. 3;

FIG. 5 is another sectional ment of FIG. 3;

FIG. 6 is a plan view of another embodiment of the present invention; and

FIG. 7 is a sectional representation of the embodiment of FIG. 6.

representation of the embodi- DESCRIPTION OF CODE WHEEL The environment in which the code wheel of the present invention resides will now be described with reference to FIG. 1 which illustrates the coding or addressing apparatus for a mechanical sorting device. A plurality of code wheels 10 are mounted for rotation on axle 13 and this assembly is adapted to move horizontally .in rolling contact with a plurality of grooved code sections or modules which, as illustrated in FIG. 1, can be oriented with their individual code grooves in either a right-hand or left-hand position. The respective code wheels can also be placed in a corresponding right-hand or left-hand position to represent a binary coded address. In this manner the code wheel assembly will pass over all groups of grooved code sections except that group of sections whose orientation coincides with the orientation of the code wheels.

As illustrated in both FIGS. 1 and 2, a mismatch exists between the code wheel assembly and the grooved track sections when the code wheel assembly is in position A while there is a coincidence between code orientations and section orientations when the code wheel assembly is in position B. As illustrated in FIG. 2, this coincidence allows the code wheel assembly to drop slightly and this vertical movement may be utilized to release the contents from a tray attached to the code wheel assembly by way of axle 13.

As indicated in FIG. 1, the code wheels must be capable of being repositioned after assembly on axle I3. This positioning may be accomplished manually or automatically as by positioning arm 14 as illustrated in FIG. 2.

The code wheel of the present invention is adapted to be manufactured more easily and more economically than code wheels of the prior art. To this end, the code wheel of the present invention is adapted to be formed or molded, as byinjection molding, as a single unitary device. It will be remembe red, however, thatthe code wheel of the type employed in a mechanical sorting apparatus must be capable of being placed in either of two stable states. The code wheel of the present is adapted to reside in two such stable states with change from one to the other of the stable states being accommodated by the particular type of material employed which is flexible enough to allow for translation from one to the other of the stable states and yet rigid enough to provide the mechanical support which is required of the code wheel. Various plastic materials are available which possess the required material characteristics. However, a particular preferred material is polypropylene which material is also readily employed in injection molding.

Since the wheel rim is to move axially between its two stable positions, the required supports can be pivotally mounted on the wheel hub at a location between the two rim positions which have been designated as the stable positions and the length of the support can be made of that dimension required for connection to the wheel rim. With this configuration, the code wheel structure will have natural dimensions for residing in either one of the stable states. However, the rim supports or the rim itself will have to be deformed in moving from one stable state to the other. The only additional requirement of the configuration is that the various rim supports by symmetrically mounted about the axis of the wheel.

Two embodiments of the present invention are disclosed in FIGS. 3 and 6 respectively. The embodiment of FIG. 3 employs a spoked configuration while the embodiment of FIG. 6 employs a flexible conical web. Referring now to FIG. 3, the embodiment shown there includes hub which is adapted to be rotatably mounted on an axial rod. Wheel rim 21 is attached to hub 20 by a plurality of spokes 22 which is pivotally joined to both rim 21 and hub 20. In addition, rim 2] is provided with a plurality of guide members 24 which project inwardly from rim 21 and serve to prevent skewing of rim 21 when it is translated or transferred from one of its stable positions to the other.

FIG. 4, which is a cross-sectional view of FIG. 3 more readily illustrates the features of the present invention as contained in that embodiment. This FIG. also illustrates a second stable position in phantom form. To provide for translation between the two stable states, the respective spokes 22 are connected to the periphery of hub 20 at a location which is intermediate between the two stable states of rim 21. The respective spokes 22 are flared inwardly at each end as illustrated at 23 to provide the necessary flexibility for the pivotal mounting.

A more detailed view of the respective guide members 24 is illustrated in FIG. 5 which is a separate cross-sectional view of FIG. 3 that is distinct from the cross-sectional view of FIG. 4. FIG. 5 illustrates the manner in which the guide members can be translated by a linear motion from one stable state to another as rim 21 is translated from one stable state to another. In order to provide sufiicient supporting surface, guide member 24 is formed with a suitable support extension 25.

FIG. illustrates another embodiment of the invention in which the wheel rim 31 is attached to hub 30 by way of a flexible conical web 32 to allow for the translation of rim 31 from one to the other of its stable states. FIG. 7 is a cross-sectional view of the embodiment of FIG. 6 and illustrates the structure of this webbed embodiment. Particularly, the inner and outer circumferences of web 32 are flared inwardly at the respective connections with rim 31 and hub 30. This necking in which is illustrated at 33 allows the respective connections to serve as pivots to more readily facilitate translation of rim 31 between one and the other of its stable states.

It will be noted from FIG. 7 that the approximate conical element of web 32 is of a dimension greater. than the difference between the inner radius of rim 31 and the outer radius of hub 30. Thus the two stable states of rim 31 will reside at those locations where the projection of the conical element upon a vertical plan coincides with the difference between the above two stated radii.

With each embodiment, translation between the two stable states is accommodated by the flexibility of the material employed so that either the rim or the respective supporting members can be distorted during the translation. With the spoked embodiment of FIG. 3, rim 21 will be distorted toward a polygonal shape to accommodate pivoting of the respective spokes 22 to the secondstable position. On the other hand, with the webbed embodiment of FIG. 6, web 32 will be folded back upon itself during the translation of rim 31 from one stable position to the other. The material resistance to these respective distortions serves to urge the respective rims toward the nearest stable position.

While the present invention has been particularly described for employment in a sorting apparatus such as would be employed for sorting mail, packages as well as other articles, it will be appreciated that the present invention is adaptable for use with any conveyor system that requires the designation of a particular element of a conveyor system and comparison of that designation with a plurality of receiving station addresses.

It will be further appreciated that while only specific embodiments of the present invention and methods of forming the present invention have been described and illustrated, changes and modifications therein will be apparent to one skilled in the art which changes and modifications will nevertheless be within the spirit and scope of the invention as claimed.

We claim:

1. A wheel comprising:

a hub;

a rim adapted to reside in either one of two stable positions symmetrically arranged about said hub in an axial direction; and

supporting means connected to said rim and to said hub and adapted to provide for translation of said rim between one and the other of said stable positions.

2. A wheel according to claim 1 which is provided with a unitary form of flexible material.

3. A wheel according to claim 2 wherein the material is polypropylene.

4. A wheel according to claim 1 wherein the length of the supporting means is greater than the difference between the inside rim radius and the outer hub radius.

5. A wheel according to claim 4 wherein the supporting member is provided with surfaces which surfaces converge to form necks at the respective connections to the hub and to the rim.

6. A wheel according to claim 4 wherein the supporting means is formed of an approximately conical web.

7. A wheel according to claim 6 wherein said web is provided with a thickness sufficiently small to allow the web to fold over itself during translation of said rim from one stable position to another.

8. A wheel according to claim 4 wherein the supporting means includes a plurality of spokes.

9. A wheel according to claim 8 wherein the rim is provided with a thickness sufficiently small to allow distortion of the rim during translation of said rim from one stable position to another.

10. A wheel according to claim 8 wherein said rim is provided with a plurality of inwardly extending guide members to prevent skewing of the rim during translation from one stable position to another. 

1. A wheel comprising: a hub; a rim adapted to reside in either one of two stable positions symmetrically arranged about said hub in an axial direction; and supporting means connected to said rim and to said hub and adapted to provide for translation of said rim between one and the other of said stable positions.
 2. A wheel according to claim 1 which is provided with a unitary form of flexible material.
 3. A wheel according to claim 2 wherein the material is polypropylene.
 4. A wheel according to claim 1 wherein the length of the supporting means is greater than the difference between the inside rim radius and the outer hub radius.
 5. A wheel according to claim 4 wherein the supporting member is provided with surfaces which surfaces converge to form necks at the respective connecTions to the hub and to the rim.
 6. A wheel according to claim 4 wherein the supporting means is formed of an approximately conical web.
 7. A wheel according to claim 6 wherein said web is provided with a thickness sufficiently small to allow the web to fold over itself during translation of said rim from one stable position to another.
 8. A wheel according to claim 4 wherein the supporting means includes a plurality of spokes.
 9. A wheel according to claim 8 wherein the rim is provided with a thickness sufficiently small to allow distortion of the rim during translation of said rim from one stable position to another.
 10. A wheel according to claim 8 wherein said rim is provided with a plurality of inwardly extending guide members to prevent skewing of the rim during translation from one stable position to another. 